The Imaging Core will provide essential support for the PET studies (Projects 1-3) and the MR studies (Project 2) proposed in this application. In these studies, multiple radiotracers will be administered intravenously to all research participants in conjunction with PET imaging. In Project 1, Parkinson's disease (PD) patients and healthy volunteer subjects will be scanned with [ [18] F]-FDG PET (to measure glucose metabolism), [[15] 0]-H20 PET (to visualize cerebral blood flow) and [ [82]Rb] PET (to assess blood brain barrier (BBB) permeability). In Project 2, PD patients will be scanned with [18] F-FDG (for glucose metabolism), [[11] C]-PIB (to detect protein aggregation), and [[18] F]-FPCIT (to trace striatal dopamine transporter binding). In Project 3, subjects will also undergo FPCIT PET imaging. The PET studies will be supported by the cyclotron/PET group within the Imaging Core. The planned fMRI studies in Project 2 will be supported by the MR group within the Imaging Core. The cyclotron/PET unit at the Feinstein Institute (FIMR) has been performing multi-tracer PET studies in patients with PD and other neurodegenerative diseases for over 20 years. The PET imaging lab and the cyclotron unit are located adjacent to each other in the basement ofthe FIMR. Resources are in place for the routine production and utilization of [18] F]-FDG, [[18] Oj-H2O, [ [11] C]-PIB, and [[18] F]-FPC1T for research studies. (The [[82] Rb] PET studies will utilize a commercially available generator as described below). The high-field MRI unit is located in the Department of Radiology of North Shore University Hospital, approximately 200 ft. from The Feinstein Institute building. The MR investigators within the Imaging Core share office and laboratory space with the other imaging investigators and often work together on disease-related projects that involve multiple imaging modalities. These investigators will optimize the MR image acquisition protocols proposed for Project 2 and will collect and process the relevant MR imaging data.